feat: New Garbage Collection Metrics Sampler for .NET 6+

src/Agent/NewRelic/Agent/Core/AgentHealth/AgentHealthReporter.cs

@@ -683,6 +683,7 @@ private void CollectOneTimeMetrics()
             ReportInfiniteTracingOneTimeMetrics();
             ReportIfLoggingDisabled();
             ReportIfInstrumentationIsDisabled();
+            ReportIfGCSamplerV2IsEnabled();
         }
 
         public void CollectMetrics()
@@ -838,5 +839,15 @@ private void ReportIfInstrumentationIsDisabled()
                 ReportSupportabilityGaugeMetric(MetricNames.SupportabilityIgnoredInstrumentation, ignoredCount);
             }
         }
+
+        private void ReportIfGCSamplerV2IsEnabled()
+        {
+            if (_configuration.GCSamplerV2Enabled)
+            {
+                ReportSupportabilityCountMetric(MetricNames.SupportabilityGCSamplerV2Enabled);
+            }
+
+        }
+
     }
 }

src/Agent/NewRelic/Agent/Core/AgentManager.cs

@@ -115,7 +115,7 @@ private AgentManager()
             }
 
             _container = AgentServices.GetContainer();
-            AgentServices.RegisterServices(_container, bootstrapConfig.ServerlessModeEnabled);
+            AgentServices.RegisterServices(_container, bootstrapConfig.ServerlessModeEnabled, bootstrapConfig.GCSamplerV2Enabled);
 
             // Resolve IConfigurationService (so that it starts listening to config change events) and then publish the serialized event
             _container.Resolve<IConfigurationService>();
@@ -162,7 +162,7 @@ private AgentManager()
                 Log.Info("The New Relic agent is operating in serverless mode.");
             }
 
-            AgentServices.StartServices(_container, bootstrapConfig.ServerlessModeEnabled);
+            AgentServices.StartServices(_container, bootstrapConfig.ServerlessModeEnabled, bootstrapConfig.GCSamplerV2Enabled);
 
             // Setup the internal API first so that AgentApi can use it.
             InternalApi.SetAgentApiImplementation(agentApi);

src/Agent/NewRelic/Agent/Core/Config/BootstrapConfiguration.cs

@@ -2,11 +2,14 @@
 // SPDX-License-Identifier: Apache-2.0
 
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using NewRelic.Agent.Core.Configuration;
 using NewRelic.Agent.Core.Utilities;
 using NewRelic.Agent.Extensions.Logging;
 using NewRelic.Agent.Core.SharedInterfaces;
+using NewRelic.Agent.Extensions.SystemExtensions.Collections.Generic;
 
 namespace NewRelic.Agent.Core.Config
 {
@@ -21,6 +24,7 @@ public interface IBootstrapConfiguration
         string ServerlessFunctionName { get; }
         string ServerlessFunctionVersion { get; }
         bool AzureFunctionModeDetected { get; }
+        bool GCSamplerV2Enabled { get; }
     }
 
     /// <summary>
@@ -64,6 +68,7 @@ public BootstrapConfiguration(configuration localConfiguration, string configura
         public BootstrapConfiguration(configuration localConfiguration, string configurationFileName, Func<string, ValueWithProvenance<string>> getWebConfigSettingWithProvenance, IConfigurationManagerStatic configurationManagerStatic, IProcessStatic processStatic, Predicate<string> checkDirectoryExists, Func<string, string> getFullPath)
         {
             ServerlessModeEnabled = CheckServerlessModeEnabled(localConfiguration);
+            GCSamplerV2Enabled = CheckGCSamplerV2Enabled(TryGetAppSettingAsBoolWithDefault(localConfiguration, "GCSamplerV2Enabled", false));
             DebugStartupDelaySeconds = localConfiguration.debugStartupDelaySeconds;
             ConfigurationFileName = configurationFileName;
             LogConfig = new BootstrapLogConfig(localConfiguration.log, processStatic, checkDirectoryExists, getFullPath);
@@ -133,6 +138,8 @@ public string AgentEnabledAt
 
         public bool AzureFunctionModeDetected => ConfigLoaderHelpers.GetEnvironmentVar("FUNCTIONS_WORKER_RUNTIME") != null;
 
+        public bool GCSamplerV2Enabled { get; private set;}
+
         private bool CheckServerlessModeEnabled(configuration localConfiguration)
         {
             // We may need these later even if we don't use it now.
@@ -154,6 +161,11 @@ private bool CheckServerlessModeEnabled(configuration localConfiguration)
             return localConfiguration.serverlessModeEnabled;
         }
 
+        private bool CheckGCSamplerV2Enabled(bool localConfigurationGcSamplerV2Enabled)
+        {
+            return localConfigurationGcSamplerV2Enabled || (ConfigLoaderHelpers.GetEnvironmentVar("NEW_RELIC_GC_SAMPLER_V2_ENABLED").TryToBoolean(out var enabledViaEnvVariable) && enabledViaEnvVariable);
+        }
+
         private void SetAgentEnabledValues()
         {
             _agentEnabledWithProvenance = TryGetAgentEnabledFromWebConfig();
@@ -204,6 +216,30 @@ private ValueWithProvenance<bool> TryGetAgentEnabledSetting(Func<string, ValueWi
             return null;
         }
 
+        private Dictionary<string, string> TransformAppSettings(configuration localConfiguration)
+        {
+            if (localConfiguration.appSettings == null)
+                return new Dictionary<string, string>();
+
+            return localConfiguration.appSettings
+                .Where(setting => setting != null)
+                .Select(setting => new KeyValuePair<string, string>(setting.key, setting.value))
+                .ToDictionary(IEnumerableExtensions.DuplicateKeyBehavior.KeepFirst);
+        }
+
+        private bool TryGetAppSettingAsBoolWithDefault(configuration localConfiguration, string key, bool defaultValue)
+        {
+            var value = TransformAppSettings(localConfiguration).GetValueOrDefault(key);
+
+            bool parsedBool;
+            var parsedSuccessfully = bool.TryParse(value, out parsedBool);
+            if (!parsedSuccessfully)
+                return defaultValue;
+
+            return parsedBool;
+        }
+
+
         private class BootstrapLogConfig : ILogConfig
         {
             private readonly string _directoryFromLocalConfig;

src/Agent/NewRelic/Agent/Core/Configuration/DefaultConfiguration.cs

@@ -1912,7 +1912,6 @@ public bool UtilizationDetectAzureFunction
             }
         }
 
-
         public int? UtilizationLogicalProcessors
         {
             get
@@ -2163,7 +2162,8 @@ public string AzureFunctionResourceIdWithFunctionName(string functionName)
                 return string.Empty;
             }
 
-            return $"{AzureFunctionResourceId}/functions/{functionName}";        }
+            return $"{AzureFunctionResourceId}/functions/{functionName}";
+        }
 
         public string AzureFunctionResourceGroupName
         {
@@ -2466,6 +2466,8 @@ public TimeSpan StackExchangeRedisCleanupCycle
             }
         }
 
+        public bool GCSamplerV2Enabled => _bootstrapConfiguration.GCSamplerV2Enabled;
+
         #endregion
 
         #region Helpers

src/Agent/NewRelic/Agent/Core/Configuration/ReportedConfiguration.cs

@@ -711,6 +711,8 @@ public ReportedConfiguration(IConfiguration configuration)
 
         public string AzureFunctionResourceIdWithFunctionName(string functionName) => _configuration.AzureFunctionResourceIdWithFunctionName(functionName);
 
+        [JsonProperty("gc_sampler_v2.enabled")]
+        public bool GCSamplerV2Enabled => _configuration.GCSamplerV2Enabled;
 
         public IReadOnlyDictionary<string, string> GetAppSettings()
         {

src/Agent/NewRelic/Agent/Core/DependencyInjection/AgentServices.cs

@@ -3,7 +3,9 @@
 
 using System;
 using System.Collections.Generic;
+#if NETFRAMEWORK
 using System.Threading;
+#endif
 using NewRelic.Agent.Api;
 using NewRelic.Agent.Configuration;
 using NewRelic.Agent.Core.AgentHealth;
@@ -58,7 +60,8 @@ public static IContainer GetContainer()
         /// </summary>
         /// <param name="container"></param>
         /// <param name="serverlessModeEnabled"></param>
-        public static void RegisterServices(IContainer container, bool serverlessModeEnabled)
+        /// <param name="gcSamplerV2Enabled"></param>
+        public static void RegisterServices(IContainer container, bool serverlessModeEnabled, bool gcSamplerV2Enabled)
         {
             // we register this factory instead of just loading the storage contexts here because deferring the logic gives us a logger
             container.RegisterFactory<IEnumerable<IContextStorageFactory>>(ExtensionsLoader.LoadContextStorageFactories);
@@ -91,9 +94,18 @@ public static void RegisterServices(IContainer container, bool serverlessModeEna
             container.Register<IPerformanceCounterProxyFactory, PerformanceCounterProxyFactory>();
             container.Register<GcSampler, GcSampler>();
 #else
-            container.RegisterInstance<Func<ISampledEventListener<Dictionary<GCSampleType, float>>>>(() => new GCEventsListener());
-            container.RegisterInstance<Func<GCSamplerNetCore.SamplerIsApplicableToFrameworkResult>>(GCSamplerNetCore.FXsamplerIsApplicableToFrameworkDefault);
-            container.Register<GCSamplerNetCore, GCSamplerNetCore>();
+            if (gcSamplerV2Enabled)
+            {
+                container.Register<IGCSamplerV2ReflectionHelper, GCSamplerV2ReflectionHelper>();
+                container.Register<IGCSampleTransformerV2, GCSampleTransformerV2>();
+                container.Register<GCSamplerV2, GCSamplerV2>();
+            }
+            else
+            {
+                container.RegisterInstance<Func<ISampledEventListener<Dictionary<GCSampleType, float>>>>(() => new GCEventsListener());
+                container.RegisterInstance<Func<GCSamplerNetCore.SamplerIsApplicableToFrameworkResult>>(GCSamplerNetCore.FXsamplerIsApplicableToFrameworkDefault);
+                container.Register<GCSamplerNetCore, GCSamplerNetCore>();
+            }
 #endif
 
             container.Register<IBrowserMonitoringPrereqChecker, BrowserMonitoringPrereqChecker>();
@@ -225,7 +237,7 @@ public static void RegisterServices(IContainer container, bool serverlessModeEna
         /// <summary>
         /// Starts all of the services needed by resolving them.
         /// </summary>
-        public static void StartServices(IContainer container, bool serverlessModeEnabled)
+        public static void StartServices(IContainer container, bool serverlessModeEnabled, bool gcSamplerV2Enabled)
         {
             if (!serverlessModeEnabled)
                 container.Resolve<AssemblyResolutionService>();
@@ -242,7 +254,12 @@ public static void StartServices(IContainer container, bool serverlessModeEnable
             samplerStartThread.Start();
 #else
             if (!serverlessModeEnabled)
-                container.Resolve<GCSamplerNetCore>().Start();
+            {
+                if (!gcSamplerV2Enabled)
+                    container.Resolve<GCSamplerNetCore>().Start();
+                else
+                    container.Resolve<GCSamplerV2>().Start();
+            }
 #endif
             if (!serverlessModeEnabled)
             {

src/Agent/NewRelic/Agent/Core/Metrics/MetricNames.cs

@@ -837,6 +837,7 @@ public static string GetSupportabilityInstallType(string installType)
         public const string SupportabilityLoggingFatalError = "Supportability/DotNET/AgentLogging/DisabledDueToError";
 
         public const string SupportabilityIgnoredInstrumentation = SupportabilityDotnetPs + "IgnoredInstrumentation";
+        public const string SupportabilityGCSamplerV2Enabled = SupportabilityDotnetPs + "GCSamplerV2/Enabled";
 
         #endregion Supportability
 
@@ -1034,6 +1035,20 @@ public static string GetThreadpoolThroughputStatsName(ThreadpoolThroughputStatsT
 
             { GCSampleType.LOHSize , "GC/LOH/Size" },
             { GCSampleType.LOHSurvived, "GC/LOH/Survived" },
+
+            { GCSampleType.LOHCollectionCount, "GC/LOH/Collections" },
+            { GCSampleType.POHCollectionCount, "GC/POH/Collections" },
+
+            { GCSampleType.TotalHeapMemory, "GC/Heap/Total" },
+            { GCSampleType.TotalCommittedMemory, "GC/Heap/Committed" },
+            { GCSampleType.TotalAllocatedMemory, "GC/Heap/Allocated" },
+
+            { GCSampleType.Gen0FragmentationSize, "GC/Gen0/Fragmentation" },
+            { GCSampleType.Gen1FragmentationSize, "GC/Gen1/Fragmentation" },
+            { GCSampleType.Gen2FragmentationSize, "GC/Gen2/Fragmentation" },
+            { GCSampleType.LOHFragmentationSize, "GC/LOH/Fragmentation" },
+            { GCSampleType.POHFragmentationSize, "GC/POH/Fragmentation" },
+            { GCSampleType.POHSize, "GC/POH/Size" }
         };
 
         public static string GetGCMetricName(GCSampleType sampleType)

src/Agent/NewRelic/Agent/Core/Samplers/GCSampleType.cs

@@ -0,0 +1,90 @@
+// Copyright 2020 New Relic, Inc. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+namespace NewRelic.Agent.Core.Samplers
+{
+    public enum GCSampleType
+    {
+        /// <summary>
+        /// Gen 0 heap size as of the current sample
+        /// </summary>
+        Gen0Size,
+        Gen0Promoted,
+        /// <summary>
+        /// Gen 1 heap size as of the current sample
+        /// </summary>
+        Gen1Size,
+        Gen1Promoted,
+        /// <summary>
+        /// Gen 2 heap size as of the current sample
+        /// </summary>
+        Gen2Size,
+        Gen2Survived,
+        /// <summary>
+        /// Large object heap size as of the current sample
+        /// </summary>
+        LOHSize,
+        LOHSurvived,
+        HandlesCount,
+        InducedCount,
+        PercentTimeInGc,
+        /// <summary>
+        /// Gen 0 heap collection count since the last sample
+        /// </summary>
+        Gen0CollectionCount,
+        /// <summary>
+        /// Gen 1 heap collection count since the last sample
+        /// </summary>
+        Gen1CollectionCount,
+        /// <summary>
+        /// Gen 2 heap collection count since the last sample
+        /// </summary>
+        Gen2CollectionCount,
+
+        // the following are supported by GCSamplerV2 only
+        /// <summary>
+        /// Pinned object heap size
+        /// </summary>
+        POHSize,
+        /// <summary>
+        /// Large object heap collection count since the last sample
+        /// </summary>
+        LOHCollectionCount,
+        /// <summary>
+        /// Pinned object heap collection count since the last sample
+        /// </summary>
+        POHCollectionCount,
+        /// <summary>
+        /// Total heap memory in use as of the current sample
+        /// </summary>
+        TotalHeapMemory,
+        /// <summary>
+        /// Total committed memory in use as of the current sample
+        /// </summary>
+        TotalCommittedMemory,
+        /// <summary>
+        /// Total heap memory allocated since the last sample
+        /// </summary>
+        TotalAllocatedMemory,
+        /// <summary>
+        /// Fragmentation of the Gen 0 heap as of the current sample
+        /// </summary>
+        Gen0FragmentationSize,
+        /// <summary>
+        /// Fragmentation of the Gen 1 heap as of the current sample
+        /// </summary>
+        Gen1FragmentationSize,
+        /// <summary>
+        /// Fragmentation of the Gen 2 heap as of the current sample
+        /// </summary>
+        Gen2FragmentationSize,
+        /// <summary>
+        /// Fragmentation of the Large Object heap as of the current sample
+        /// </summary>
+        LOHFragmentationSize,
+        /// <summary>
+        /// Fragmentation of the Pinned Object heap as of the current sample
+        /// </summary>
+        POHFragmentationSize,
+    }
+}